Abstract

Current structural models for amorphous hydrogenated carbon (a-C:H) are called into question on the basis of neutron-diffraction experimental work carried out al the ISIS pulsed neutron source (UK) on a-C:H. The nature of the neutron source allows the collection of data over an exceptionally wide dynamic range that ensures a real-space resolution sufficient to allow direct observation, for the first time, of contributions from the principal C-C bond types. The data also reveal details of the C-H correlations, and the presence of trapped molecular hydrogen.